Recently, in the field of manufacturing semiconductors, various fine processing techniques have been and are presently developed as the size of semiconductor elements reduces and the integration degree of semiconductor elements increases. Of these techniques, the CMP (chemical mechanical polishing) technique is one of the essential elements for making a buried structure such as a buried metal wiring or a buried element separation.
In the case where a surface to be polished, which is a surface having an irregularity (recesses and projections), is smoothed by the CMP, the polishing rate is influenced by the surface state of the polishing pad of the CMP apparatus employed. Conventionally, the state of the surface of the polishing pad is designed such that abrasives within the slurry are sufficiently held on the surface of the polishing pad.